The next Gordon Research Conference on The Biology of Aging (February, 1985) will focus on the regulation of physiological functions by hormones and neurotransmitters during aging. Specific physiological functions exhibiting age related deterioration such as reproduction, immunocompetence, neurotransmission, and control of energy metabolism will be emphasized. In addition, impaired molecular action of steroids, cyclic nucleotides, catecholamines, and calcium will be explored. Most important, in all cases age related changes in physiology will be related to molecular alterations in endocrine and neuroendocrine regulation. This approach offers a unique opportunity to consider modulation by appropriate endocrine and neuroendocrine manipulations.